Male-female electric contact blade and plug



Aug. 23, 1966 F. KLUMPP, JR 3,268,847

MALE-FEMALE ELECTRIC CONTACT BLADE AND PLUG Filed April 14, 1964 2 Sheets -Sheet 1 5 3 9, /0 l3 3 m 7 /4 3 5 z L I i m A w x INVENTOR. FFRD/IVA/VD lfl UMP/Z JP.

BY W

S ATTORMEYS.

Aug. 23, 1966 F. KLUMPP, JR 3, ,8

MALE-FEMALE ELECTRIC CONTACT BLADE AND PLUG Filed April 14, 1964 2 Sheets-Sheet 2 \34 INVENTOR. i G I 2 Ft'kD/NAIA/D m UMPP, 12

United States Patent 3,268,847 MALE-FEMALE ELECTRIC CONTACT BLADE AND PLUG Ferdinand Klumpp, Jr., Union, N.J., assignor to Heyman Manufacturing Company, Kenilworth, N.J., a corporation of New Jersey Filed Apr. 14, 1964, Ser. No. 360,485 4 Claims. (Cl. 339--14) The present invention relates to a male-female electric contact blade and three-prong adapter plug and is a continuation in part of my application Ser. No. 351,308, filed March 12, 1964, now abandoned.

With todays usage of many electric appliances, many of which draw substantial amounts of current, it is oftentimes essential that such appliances be provided with a means of grounding. In many instances the appliances come provided with three-pronged plugs, the third prong usually being in the form of a round ground pin. While almost every standard electric outlet is adapted to re-.

ceive the standard electric contact blade, not every outlet is adapted to receive a round ground pin.

Where an electrical appliance comes provided with a three-prong plug and no three-pronged receptacle is available, an adapter must be provided to convert such threepronged plug into a two-pronged unit adapted to be used in the standard electric two-prong receptacle.

In most instances the adapter is provided with three openings, two to receive the electric contact blades and the third to accept the round ground pin. The ground pin usually has a lead to a ground Wire which can then be used to perform the function of the ground pin by being separately grounded.

The blades in such adapter plug must be adapted to receive the conventional blades of the three-prong plug and also to protrude as a conventional blade for use in the standard outlet.

In the past such blades have been made of a single piece of metal with a second portion forming the second part of the female lips riveted or welded to one section of the blade providing a resilient grip. Such blades are then usually molded in rubber or plastic or single piece folded blades with integral holding lugs have been provided for resiliently and firmly holding such blades in plugs, such as Bakelite plugs.

According to the present invention a simple threeprong adapter plug and one piece folded metal malefemale contact blade or combination blade is provided. The blade is especially adapted to be molded into an adapter plug to adapt a three-prong plug for use in a two-prong outlet.

Although such novel feature or features believed to be characteristic of the invention and are pointed out in the claims, the invention and the manner in which it may be carried out, may be further understood by reference to the description following and the accompanying drawings.

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a side view of the embodiment of FIG. 1. 3 FIG. 3 is a plan view of another embodiment of the present invention.

FIG. 4 is a side view of the embodiment of FIG. 3.

FIG. 5 is a section of an adapter plug with a die holding the blade of the present invention inside a molded plug.

3,268,847 Patented August 23, 1966 FIG. 5a is a section showing the blade of FIGS. 3 and 4 with a die holding it inside a molded plug.

FIG. 6 is a section of the embodiment of FIG. 5 at lines 66 showing a die removed.

FIG. 7 is a perspective of an adapter plug.

FIG. 8 is a section of the adapter plug of FIG. 7 with a three-prong plug engaged.

FIG. 9 is a side elevation of a combination blade of the present invention.

FIG. 10 is a plan view of FIG. 9.

FIG. 11 is a detail modification of the blade of FIGS. 9 and 10.

FIG. 12 is a polarized blade set of the present invention.

FIG. 13 is a further embodiment of the blade of the present invention.

Referring now to the figures in greater detail, where like reference numbers denote like parts in the various figures.

The male-female blade 1 and the male-female blade 1a as shown in FIGS. 3, 4 and 5a comprise essentially a single piece of metal with a center fold 2 joining the sections 3, 4 of the blade. The corners 5 of the blade end 6 are beveled and include a conventional end opening 7. The two sections 3, 4 of the blade 1 are held together by a crimped tongue 8 which is intrinsic to one of the blade sections 3 and passes through an opening 9 in the other blade section 4. The tongue 8 is crimped in the form of a U grasping and holding the blade sections 3, 4 together near their upper end.

Extending from each blade section 3, 4 are leg portions 10,11 oppositely flared away from the main joined blade sections 3, 4 and angled back to join each other near the leg ends at a point 12 and again flared open in the form of two lips 13, 14 forming the femaleportion 15 of the male-female blade 1.

The embodiment of the male-female blade 1a shown in FIGS. 3, 4 and 5a includes recessed shoulders 17, 1-8 which are narrower than the blade leg portions 10, 11.

The blade leg portions 10, 11 have some spring resilience from a fulcrum formed by the crimping tongue 8 and opening 9 tending to' keep the legs 10, 1'1 closed at the point of junction 12, thus an inserted electric contact blade is tended to be held firmly as shown in FIG. 8. The blades 1, 1a are made of conventional electric conducting metal such as brass.

It has been found advantageous as shown in FIG. 13 to provide the male-female blade 1b with an angled lip 14a in order to provide for the male-female blade 1 holding firm once it has been molded into a plug.

In the manufacture of an adapter plug such as shown in FIG. 7, the plug isusually molded about the blades 1, 1a and a round ground pin receptacle 20. The blades and pins are mounted on dies 21, 22 (no die shown for the ground pin receptacle 20) to firmly hold the blades 1, 1a in a mold while the plug 19 is cast in rubber, plastic or other appropriate material. The dies 21, 22 must snugly fit between the legs 10, 11 of the blades during molding so that the inner electric contact surfaces of the legs 10, 11 are not fouled by plastic in molding which would spoil the conductive characteristics of the blades 1, 1a. After molding, the dies 21, as shown in FilG. 6 are removed providing openings 23, each adapted to receive a blade 24 from a'three-prong .3 plug 25 which is then adapted to a conventional tworeceptacle electric outlet by the adapter plug 19. The plastic of molding usually flows through the opening 9 in the blades 1, 1a firmly holding the blades 1, 1a in the molded plug 19. The plastic usually has some resilience.

The blades 24 from a three-prong plug 25 are usually of a conventional width, near one-quarter inch as are the male-female blades 1, 1a of the present invention which are adapted to the usual two-opening electric receptacle. The openings 23, adapted to receive plug blades 24, extend to the point where the legs 10, 11 commence to flare. The openings 23 may not be much longer than the blades 24 which are to be received, since an extra length of the opening might not provide a firm grip of such blades 24 and is conducive of movement of the blade 24 within the openings 23.

Maintaining the openings 23 of proper size in molding the plug 19 has in the past been inherent with difiiculties since the dies 21 which hold the blade 1 must be provided with flanges 26 extending beyond the thickness of the blade 1 and covering sides of the legs 10, 11 to prevent the inflow of plastic during molding and a fouling of the electrical conductive characteristic of the blade 1. A thick flange 26 provides an opening 23 that is too long while the thin flanges 26 have proven to be delicate and easily broken, destroying their utility or requiring frequent replacement.

The die 22 is provided with thick flanges 27 adapted to conform to the recessed shoulders 17, 18 of the blade 1a. While the legs 10, 11 of the blade 1a are narrower than the width of the male portion of the blade 1a, the reduction in size does not affect the electrical characteristics of the blade 1a while permitting the opening 23 to be of proper length to receive a blade 24. The die 22 is stronger, less easily broken and still effectively prevents the inflow of plastic during molding and a fouling of the electrical conductive characteristics of the blade 1a.

The blade 1b may be provided with recessed shoulders 17 not shown in FIG. 13 as provided for the blade 1a as shown in FIG. 3.

Irrespective of the use of shoulders 17 or conventional blade lips 13, 14 the molding process is unaffected and the dies 21, 22 depending upon the shoulders of the blade may be used with the same effect without the expense of retooling to use the male-female blade 1b.

The flanges 26, 27 of the dies 21, 22 keep the area between the legs 10, 11 free of the molding dielectric material and reassure electric contact not being fouled by the plastic at the junction points 12 between the legs 10, 11, While the lip 14a embeds itself in the dielectric plastic reassuring that any untoward pull on the blade 1b itself will not disengage it from the adapter plug 19.

The shape of the opening 23 is unchanged, using the male-female blade 1b as is the effective electric contact between the male-female blade and an inserted blade as contrasted with other embodiments of the blade.

The exact angle of the lip 14:: is not critical but must be such as to become firmly embedded in the plastic and be resistant to being slid out of the plug 19 under tugging pressure.

The male-female blade 28 shown in FIGS. 9, 10, 11 is a combination adaption of the present invention with wire crimping means 29, 29a formed on the body of the blade section 30. Crimping arms 31, 31a are adapted to receive lead wires not shown for combination application of use of the blades of the present invention.

The male-female blade set 32 comprising blades 33, 34 as shown in FIG. 12 are polarized and adapted to be provided in stamping strips providing no wastage of stamping strip metal as shown in my application Ser. No. 715,026 filed February 13, 1958, now issued as US. Patent No. 3,149,898.

Where male-female blades are required for polarized applications, the blade set 32 matches polarizing receptacles. The added width of blade end 36, while on a standard shank 37, cannot enter the wrong receptacle of a polarized outlet. The blade end 38 may fit any receptacle. In the case of the receptacle use of the blade set 32 in a three-prong plug, the receptacle portion 35 of the blades 33, 34.need no special adaptation since polarity must be maintained uniformly in order to prop erly plug in a three-prong plug (see FIG. 8).

The terms and expressions which are employed are used as terms of description; it is recognized, though, that various modifications are possible within the scope of the invention claimed.

Having thus described certain forms of the invention in some detail, what is claimed is:

1. A male-female electric contact blade comprising, a first blade section, a second blade section, said first and second blade sections joined by a center told, a central rigid crimp extending from one blade section through said other blade section, an integral leg portion extending from each said blade section at a point near but beyond said crimp, said leg portions resiliently meeting at a line along their width and of a narrower width than said blade sections, said narrower leg portions adapted to provide for the use of a thick flanged die when said contact blade is molded into a plug :and said leg portions adapted to receive an electric contact blade.

2. As an article of manufacture an adapter plug comprising a plastic body, an opening in said plastic body adapted to receive a ground pin, a receptacle for said ground pin (in said body, a ground wire connected to said ground pin receptacle, two openings in said body each adapted to receive electric contact blades, and male-fe-male contact blades in said openings each comprising; a first blade section; a second blade section; said first and sec ond blade sections joined by a center fold; a rigid crimp extending from one blade section through said blade sections receiving the plastic of said plug body and holding said blade firmly in said plastic plug body; an integral leg portion extending from each said blade section at a point near but beyond said crimp and said leg portions resiliently meeting at a line along their width and adapted to receive an electric contact blade; said blade portions of said contact extending beyond the plastic body of said p ug.

3. A polarized male-female electric contact blade set comprising at least two attached blades, each including a first blade section, a second blade section, said first and second blade sections joined by a center end fold, a rigid crimp extending from one blade section through said other blade section, an integral leg portion extending from each said blade section at a point near but beyond said crimp and said leg portions resiliently meeting at a line along their width and adapted to receive an electric contact blade, and one of said blades having wide end portions extending beyond the width of the blade shank and said attached blades being in side by side relationship.

4. As an article of manufacture an adapter plug comprising a plastic body, an opening in said plastic body adapted to receive a ground pin, a receptacle for said ground pin in said body, a ground wire connected to said ground .pin receptacle, two openings in said body each adapted to receive electric contact blades, and male-female contact blades in said openings each comprising; a first blade section, a second blade section, said first and second blade sections joined by a center told, a central nigid crimp extending from one blade section through said other blade section, an integral leg portion extending from each said blade section at a point near but beyond said crimp, said leg portions resiliently meeting at a line along their width and of a narrower width than said blade sections, said narrow leg portions adapted to provide for the use of a thick flanged die when said contact blade is molded into said plastic body, said leg portions adapted 5 to receive an electric contact blade and said blade portions 2,813,258 extending beyond the plastic body of said plug. 2,953,765 3,003,133 References Cited by the Examiner 3,034,084 UNITED STATES PATENTS 5 3,097,906 2/1-930 Gates 339 191 3149898 11/1-934 Clark 339-166 X 6/1940 Folsom 339191 X 6/1948 Miller 339 170 414,488 7/1949 Klumpp 339 252 1 3/ 1954 Wermine 33-9252 X 2/1957 Cahn 339262 6 Klumpp 339276 Greasley 339217 X Herman et a1 339-191 Schmder et a1. 33914 Shannon 339-253 Klumpp 339-184 Italy.

EDWARD C. ALLEN, Primary Examiner.

PATRICK A. CLIFFORD, Examiner. 

1. A MALE-FEMALE ELECTRIC CONTACT BLADE COMPRISING, A FIRST BLADE SECTION, A SECOND BLADE SECTION, SAID FIRST AND SECOND BLADE SECTIONS JOINED BY A CENTER FOLD, A CENTRAL RIGID CRIMP EXTENDING FROM ONE BLADE SECTION THROUGH SAID OTHER BLADE SECTION, AN INTEGRAL LEG PORTION EXTENDING FROM EACH SAID BLADE SECTION AT A POINT NEAR BUT BEYOND SAID CRIMP, SAID LEG PORTIONS RESILIENTLY MEETING AT A LINE ALONG THEIR WIDTTH AND OF A NARROWER WIDTH THAN SAID BLADE SECTIONS, SAID NARROWS LEG PORTIONS ADAPTED TO PROVIDE FOR THE USE OF A THICK FLANGED DIE WHEN SAID CONTACT BLADE IS MOLDED INTO A PLUG AND SAID LEG PORTIONS ADAPTED TO RECEIVE AN ELECTRIC CONTACT BLADE. 